class Point {
  int x,y;
  void setXY(int m,int n){
    x=m;
    y=n;
  }
}
public class Example4_4 {
  public static void main(String args[]) {
    Point p1,p2;
    p1=new Point();
    p2=new Point();
    System.out.println("p1的引用："+p1);
    System.out.println("p2的引用："+p2);
    p1.setXY(1111,2222);
    p2.setXY(-100,-200);
    System.out.println("p1的x，y坐标："+p1.x+","+p1.y);
    System.out.println("p2的x，y坐标："+p2.x+","+p2.y);
    p1=p2;
    System.out.println("将p2的引用赋值给p1后:");
    System.out.println("p1的引用："+p1);
    System.out.println("p2的引用："+p2);
    System.out.println("p1的x，y坐标："+p1.x+","+p1.y);
    System.out.println("p2的x，y坐标："+p2.x+","+p2.y);
  }
}
